Forage harvesters, in particular self-propelled forage harvesters, comprise a header that is provided to pick up a swath from a ground surface. The swath typically comprises crop material, which crop material is then processed by the forage harvester when picked up by the header.
In a conventional forage harvester, an operator steers the forage harvester over the swath. There, the operator aims to direct the forage harvester centrally over the swath, such that the center of gravity of the swath is aligned with the transverse center of the forage harvester. This allows a balanced processing of the swath by the forage harvester.
Attempts have been made to assist the operator in steering the forage harvester, or to (partially) automate the movement of the forage harvester. There, a camera is placed near the cabin of the forage harvester, and the images coming from the camera are processed to detect the position of the swath. This detected position of the swath can then be used and to steer the forage harvester (partially) automatically over the swath, or to assist the operator. A drawback of the known system is that processing of images from a camera is complex and time-consuming. Furthermore, changing outdoor light conditions and the fact that the swath colour is typically close to the surrounding ground colours, have as a result that swath detection by means of a camera is not possible in all circumstances. Therefore, the current system is unreliable for, and unable to assist the operator and/or to (partially) automate the forage harvester.